Oriented Strand Board (OSB) mills are highly automated and operate under a highly controlled manufacturing process. The goal of each mill is to produce as many boards as possible while maintaining board properties. As OSB products have become a preferred wood choice among builders and contractors, there has been an increased demand for OSB products with certain characteristics. These characteristics include fire retardancy, termite and fungal protection, moisture resistance, as well as others.
Due to the strictness of the OSB production process, there are limited opportunities to develop specialty boards. Additionally, since OSB is comprised of wood chips and resins, it is more difficult to impregnate the wood chips with the desired chemical formulation. As a result, specialty manufacturing of OSB is limited, specifically as it relates to fire retardant OSBs.
Current fire retardant boards utilize fire retardant formulations comprising phosphorous containing compounds, which has been found to lead to the thermal degradation of fire retardant wood products, including OSBs. In order to alleviate this concern, some fire retardant formulations have substituted phosphorous compounds with boron containing compounds. Unfortunately, boron containing formulations have been found to crosslink with the commonly used resins that are applied to the wood during the manufacturing process, causing the resulting boards to weaken and fall apart.
Accordingly, when boron containing compounds have been used, other compounds are added to counteract this reaction. For example, in U.S. Pat. No. 6,517,748, nitrogen containing organic compounds were added to the boron compounds at a ratio of 1.25:1.00 to 1.75:1.00, respectively.
Accordingly, there exists a need for an improved resin and fire retardant chemical formulation for producing fire retardant OSBs. There also exists a need for an improved process for applying fire retardant formulations to OSB precursor material that utilizes the existing OSB manufacturing process without impacting time or strength of the resulting boards.